Living dead species

[epicbattle]

I'm curious if their has been any research done on endangered animals genetic diversity. This concerns me when I hear on the news that there are less then X amount of a species. Is there a critical limit to how many animals must exist to preserve diversity? Even if we brought their numbers back, wouldn't they still be a "living dead" species? And if there is some kind of limit has research been done on saying that, as heartless as this sounds, this animal isn't worth saving?

 

Also, has anyone had any kind of progress of mutating a species a little tiny bit to create some diversity?

Any literature on this matter would be of interest.

 

Thank you very much.

[skyhook]

I would think scientists are doing that. I saw on documentary those whale scientists took tissue samples of whales, and those animals they immobilized using a tranquilizer and draw blood sample from a needle. I don't know what they do with these samples though.

no idea what is the critical number of animals to preserve diversity. Gerard Durrell said in his book he took about six(I think) pink pigeons and successfully increase the numbers in captivity. The Passenger pigeons went extinct after efforts are taken to save it. Worst case, the number is one. and after that, you can try cloning it. Charles Darwin said that there are more variations if the population is large. So it is a good thing if you can get a large population. One that is not mixed with domestic stocks. Animals adapt to domestication and become tame and some changes that make it difficult when you want to return it back to the wild.

I think when the sperm and egg combine, there is a rearrangement of some genes, that why someone look different from his siblings, and that could be a form of diversity.

An animal that rebound from near extinction, American bison. That parrot Kakapo is very rare, but well known case, might have some research done on it.

Edited July 20, 2010 by skyhook

[Schrodinger's cat]

Isn't the reason why a species requires diversity in its gene pool because of desease, resistance to pathogens, and the ability to adapt to future changes in environment? So I suppose whether a species could survive a reduction in variatibilty would depend on the previlance of inherited traits leading to serious desease amoung the serviving members, whether they face an outbreak of serious illness, and what kind of environmental changes they experience.

 

If we can artificially prop-up the population, eventually variation would again occur, but this might not occur within a reasonably timespan(millions of years is a long time to keep a preservation policy going)

 

How about splicing in some diversity from a related species? But how would you know what to change before it was too late?

 

Unfortunately, it seems likely that some species taken from the brink of extinction to an acceptable population will some day face a sudden outbreak of illness and be wiped out. But how would we know for sure which ones would be worth saving? I imagine there are more factors involved than just population numbers.

[Sisyphus]

There is a term for what you're talking about: minimum viable population

 

Also of interest:

http://en.wikipedia.org/wiki/Population_bottleneck

http://en.wikipedia.org/wiki/Small_population_size

 

So yes, clearly it can cause problems, but it's premature to write species off entirely just because they are reduced to a very small number of individuals. As you can see in the bottleneck article, there have been some extreme examples of near extinction followed by amazing recoveries, and there's even evidence that humans have gone through bottlenecks several times.